Alright, so you don't have Families in free version.
What you could do is to simulate families using one Sprite object.
Put all your images into one Sprite - frames or animations, it's up to You.
So you would have one Sprite, let's call it "Objects".
If you go with frames it will look like this
Frame 0 - Tree
Frame 1 - Building
Frame 2 - something else
Then in layout editor instead of placing different objects you will place instances of sprite "Objects" with different frames.
I would give you a example capx file, but I'm not at home at the moment.
Maybe someone can make You this one. It's really easy.